Carburizing material.



HUGH RODMAN, OF EDGEWOOD,' PENNSYLVANIA, ASSIGNOR TO BODMAN CHEMICAL COMPANY, or VERONA, PENNSYLVANIA; n CORPORATION 01 PENNSYLVANLA.

cnaBUaIzrNe MATERIAL.

1,279,160. Nobrewing.

To all whom it ma concern:

Be it known t atI, HUGH RODMAN, a

citizen of the United States, and a resident Material, of which the following is a specience to car u'rizing efiiciency, and materials fication. e

This invention has todo with the art of carburizing steel by dry, packing, and discloses a newand useful material therefor and a method of manufacturing this material. v

The essence of the invention lies in the observation that only the surface of granular carburizing materialis highly active and in the conception that. improved material may therefore be constructed bycoating an inert, or comparatively inert, particle or small mass with'a highly active covering material. I v

By this means many advantages are secured. The centers may be selected for" strength, chea ness, thermal conductivity, permanen'c volume, etc., without refer- Which are ordinarily impracticable because vof mechanical weakness or cost may be utilized as coating maternal, the inert, or. com-" paratively inert centers. furnishingthe necessary mechanical strength and the reduced amount of active material lowering the total cost. i

It is desirable, though not essential, that the covering material shouldcontain no sub-j stance that'will fuse and flow into the body of the centers, as the carburizing strength of the coating would thereby be reduced. I

therefore prefer to avoid the use of fusible material, such as the various sodium or potassium compounds ordinarily used in carburizing mixtures, and to rather use such. infusible compounds as barium carbonate and'calcium hydroxid, these being mixed with appropriate amounts of carbonaceous materials such as powdered coal or powdered leather char. For the inert centers I prefer ordinary metallurgical coke, as it is cheap, light, permanent, conductive, etc, but other materials, such as crushed brick,

charcoal, etc., may be used ifdesired.

As a concrete and successful example of my invention I will cite the following, but

Specification of Letters Patent.

with no idea of limiting the invention to the specific materials or proportions enumeratedr f I tumble 1000 pounds of coke particles, screened between and openings, with y Patented Sept. 17, 1918. Application filed July 9, 1914. Serial No. 850,067.

about 100 pounds of molasses solution ap-- proximately 1.1 density. I then gradually add about 400 pounds of coating mixture consisting of '100 parts powdered coal, 100 parts Portland cement, parts calcium hydroxid and parts barium carbonate and continue the tumbling till the coke centers are all 'well covered and smooth. I then spread the material on the floor to dry and harden for about twenty-four hours.

I It will be apparent that some reaction between the coke or carbonaceous centers and the chemical energizers may takeplace and some small carburizing efl'ect maytherefore be produced, but the carbonaceous coating produces practically all of the carburizing efi'ect. In fact where such centers have intrinsically some slight carburizing qualities (when used alone) as in the case of charcoal, I believe the coating applied not only produces substantially all the carburizing effeet, but actually cloaks 'or lessens the carburizing efi'ect intrinsically possessed-by the centers. Where a fusible energizer is used and where therefore some of the energizer flows into the carbonaceous center, the car 'burizing properties of the center are still negligible because they are cloaked by the ap lied coating of a highly active material.

ther materials and proportions will occur to those skilled in the art. For instance, the binder may be tar or other hydrocarbons, the covering may be powdered leather char or bone black: the essential idea bein that the activity of the material shall principally reside in the coating applied to the inert, or comparativel inert, centers.

Having thus escribed my invention, what I claim is:

1. A carburizing material consisting of small masses, and a material in itself highly active as a carburizing agent forming a coating for each of said masses.

2. A carburizing material consisting of carbonaceous masses, and a material in itself highly active as a carburizing agent forming an active carburizing coating fo each of said masses.

3. A carburizing material consisting of carbonaceous masses having little or no carburizing properties, and a material highly active as a carburizing materi'al forming a coating for each of said masses and cloaking the carburizing activity of the masses.

4. A carburizing material consisting of a relatively inert carbonaceous mass having bound thereto a permanent coating of energized carbon material.

5. A carburizing material consisting of small masses, coated with a coating of powdered carbonaceous material and an energizing material.

6. A carburizing material consisting of small masses having little or no carburizing properties, and an active coating for each of said masses comprising powdered carbonaceous material, an energizer, and a binder.

7. A carburizing material consisting of small inert masses and an active coating of carburizing material for each of said masses.

8. A carburizing material consisting of small coke masses and apermanent active coating for each of said masses containing carbonaceous material and an infusible enerzer. t). A carburizing material consisting of small masses having little orno carburizin properties, and an active coating for sai masses comprising powdered animal char, an energizer and a binder.

In testimony whereof, I have hereunto subscribed my name this 7th day of July, 1914.

HUGH RODMAN.

Witnesses:

E. W. 'MoCALLIsTER, ANNA C oHnR'rY. 

